Acid dyes

ABSTRACT

Compounds of the general formula (I) 
                         
a process for their preparation and their use for dyeing and/or printing organic substrates are described.

The invention relates to novel acid dyes, a process for theirpreparation and their use for dyeing organic substrates.

Acid dyes are known from e.g. EP719837A2. However, there is still a needfor acid dyes with improved properties.

The invention provides compounds of the general formula (I)

where

-   -   R¹ and R² are independently unsubstituted unbranched C₁₋₆alkyl        or unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl,    -   R³ is hydrogen, unsubstituted unbranched C₁₋₆alkyl or        unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl,    -   R⁴ and R⁵ are independently hydrogen, unsubstituted unbranched        C₁₋₆alkyl or unsubstituted branched C₃₋₆alkyl or substituted        unbranched C₁₋₆alkyl or substituted branched C₃₋₆alkyl, or        halogen,    -   R⁶ is hydrogen, unsubstituted unbranched C₁₋₆alkyl or        unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl, or unsubstituted        unbranched C₁₋₆alkoxy or unsubstituted branched C₃₋₆alkoxy or        substituted unbranched C₁₋₆alkoxy or substituted branched        C₃₋₆alkoxy, or halogen, or —NHCO—(C₁₋₆alkyl) with an unbranched        C₁₋₆alkyl group, which is substituted or unsubstituted, or        —NHCO—(C₃₋₆alkyl) with a branched C₃₋₆alkyl group, which is        substituted or unsubstituted, or —NHCONH₂,    -   R⁷ and R⁸ are independently unsubstituted unbranched C₁₋₆alkyl        or unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl or aryl or        —(CH₂)_(n)-aryl where n=1, 2, 3 or 4.

In preferred compounds of the general formula (I)

-   -   R¹ and R² are independently unsubstituted unbranched C₁₋₆alkyl        or unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl,    -   R³ is hydrogen, unsubstituted unbranched C₁₋₆alkyl or        unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl,    -   R⁴ and R⁵ are independently hydrogen, unsubstituted unbranched        C₁₋₆alkyl or unsubstituted branched C₃₋₆alkyl or substituted        unbranched C₁₋₆alkyl or substituted branched C₃₋₆alkyl, or        halogen,    -   R⁶ is hydrogen, unsubstituted unbranched C₁₋₆alkyl or        unsubstituted branched C₃₋₆alkyl or substituted unbranched        C₁₋₆alkyl or substituted branched C₃₋₆alkyl, or unsubstituted        unbranched C₁₋₆alkyl or substituted branched C₃-C₆alkyl or        unsubstituted unbranched C₁₋₆alkoxy or unsubstituted branched        C₃₋₆alkoxy or substituted unbranched C₁₋₆alkoxy    -   R⁷ unsubstituted unbranched C₁₋₆alkyl or unsubstituted branched        C₃₋₆alkyl or substituted unbranched C₁₋₆alkyl or substituted        branched C₃₋₆alkyl,    -   R⁸ is aryl or —(CH₂)_(n)-aryl where n=1, 2, 3 or 4.

The preferred compounds of formula (I) bear at least one anionicsubstituent, preferably 1 or 2 or 3 anionic substituents, of which 2anionic substituents are very particularly preferred.

Preferred anionic substituents are carboxyl and/or sulpho groups, andsulpho groups are particularly preferred.

Preferred compounds of the formula (I) preferably have 1, 2 or 3 andmore preferably 2 sulpho groups. The preferably 1, 2 or 3 sulpho groupsare preferably the further substituents or the substituents on theradicals R¹, R², R³ and/or R⁸. It is most preferable for the R⁸ radicalto bear a sulpho group.

Aryl is preferably substituted phenyl or substituted naphthyl orunsubstituted phenyl or unsubstituted naphthyl.

Preferably R¹ and R² are independently unsubstituted unbranchedC₁₋₆alkyl or unsubstituted branched C₃₋₆alkyl or substituted unbranchedC₁₋₆alkyl or substituted branched C₃₋₆alkyl or unsubstituted unbranchedC₁₋₆alkoxy or unsubstituted branched C₃₋₆alkoxy or substitutedunbranched C₁₋₆alkoxy or substituted branched C₃₋₆alkoxy. Mostpreferably, R¹ and R² are independently methyl, ethyl or isopropyl.

Preferably R³ is hydrogen, unsubstituted unbranched C₁₋₆alkyl orunsubstituted branched C₃₋₆alkyl or substituted unbranched C₁₋₆alkyl orsubstituted branched C₃₋₆alkyl or unsubstituted unbranched C₁₋₆alkoxy orunsubstituted branched C₃₋₆alkoxy or substituted unbranched C₁₋₆alkoxyor substituted branched C₃₋₆alkoxy. Most preferably R³ is hydrogen,methyl, ethyl or isopropyl, but in particular R³ is hydrogen or methyl.

Preferably R⁴ and R⁵ and R⁶ are independently hydrogen, unsubstitutedunbranched C₁₋₆alkyl or unsubstituted branched C₃₋₆alkyl, or substitutedunbranched C₁₋₆alkyl or substituted branched C₃₋₆alkyl or unsubstitutedunbranched C₁₋₆alkoxy or unsubstituted branched C₃₋₆alkoxy orsubstituted unbranched C₁₋₆alkoxy or substituted branched C₃₋₆alkoxy.Most preferably R⁴ and R⁵ are each hydrogen or methyl.

Very particular preference is further given to compounds of the formula(I) wherein R⁷ is unsubstituted unbranched C₁₋₄alkyl or unsubstitutedbranched C₃₋₄alkyl or substituted unbranched C₁₋₄alkyl or substitutedbranched C₃₋₄alkyl, but in particular hydrogen, methyl or ethyl, ofwhich methyl or ethyl are very particularly preferred. Very particularpreference is further given to compounds of the formula (I) wherein R⁸is substituted or unsubstituted phenyl or substituted or unsubstitutednaphthyl or substituted or unsubstituted —(CH₂)_(n)-phenyl orsubstituted or unsubstituted —(CH₂)_(n)-naphthyl where n=1, 2, 3 or 4,of which a —CH₂-phenylene group is very particularly preferred. Thepreferred —CH₂-phenylene groups are substituted, preferably by nitrogroups and/or sulpho groups, a sulpho group being very particularlypreferred as a substituent for the preferred —CH₂-phenylene groups.

The branched C₃₋₆alkyl groups or unbranched C₁₋₆alkyl groups and theunbranched C₁₋₆alkoxy groups or branched C₃₋₆alkoxy groups can befurther substituted with hydroxy groups or cyano groups. Preferably thealkyl groups and/or the alkoxy groups are not further substituted.

In the preferred compounds of the formula (I) the preferred alkyl groupsand the preferred alkoxy groups are methyl, ethyl, propyl, methoxy andethoxy groups. Methyl and ethyl groups are very particularly preferred.

The substituted aryl groups are preferably substituted by nitro orsulpho groups. Particular preference is given to sulpho groups assubstituents on the aryl groups.

In the compound of the formula (I) the radical having the formula (I′)

is preferably attached to the radical of the formula (I″)

either in position m (meta) or p (para). In very particularly preferredcompounds of the formula (I) the radical of the formula (I′) is p (para)attached to the radical of the formula (I″).

The invention also provides a process for preparing compounds of theformula (I). The present invention's compounds of the formula (I) can beprepared under conventional conditions in conventional processes.

In these processes, compounds of the formula (II)

which are known from the literature and in which SG is a protectivegroup such as acetyl for example and the other substituents are each asdefined above, are conventionally diazotized and coupled onto oneequivalent of a compound of the formula (III)

where the substituents are each as defined above and after theprotective group SG has been removed (by hydrolysis) the amine of theformula (IV)

is conventionally diazotized and coupled at acidic pH onto oneequivalent of a compound of the formula (V)

It is similarly possible to proceed by a process wherein first thecompound of the formula (II′)

is conventionally diazotized and coupled at acidic pH onto oneequivalent of a compound of the formula (V)

and after the protective group SG has been removed (by hydrolysis) theamine of the formula (IV′)

is conventionally diazotized and coupled onto one equivalent of acompound of the formula (III)

where the substituents are each as defined above.

The dyes of the formula (I) can be isolated from the reaction medium byconventional processes, for example by salting out with an alkali metalsalt, filtering and drying, if appropriate under reduced pressure and atelevated temperature.

Depending on the reaction and/or isolation conditions, the dyes of theformula (I) can be obtained as free acid, as salt or as mixed salt whichcontains for example one or more cations selected from alkali metalions, for example the sodium ion, or an ammonium ion or alkylammoniumcation, for example mono-, di- or trimethyl- or -ethylammonium cations.The dye can be converted by conventional techniques from the free acidinto a salt or into a mixed salt or vice versa or from one salt forminto another. If desired, the dyes can be further purified bydiafiltration, in which case unwanted salts and synthesis by-productsare separated from the crude anionic dye.

The removal of unwanted salts and synthesis by-products and partialremoval of water from the crude dye solution is carried out by means ofa semipermeable membrane by applying a pressure whereby the dye isobtained without the unwanted salts and synthesis by-products as asolution and if necessary as a solid body in a conventional manner.

The dyes of the formula (I) and their salts are particularly suitablefor dyeing or printing fibrous material consisting of natural orsynthetic polyamides in yellow to violet shades. The dyes of the formula(I) and their salts are suitable for producing Inkjet printing inks andfor using these Inkjet printing inks to print fibrous material whichconsists of natural or synthetic polyamides or cellulose (paper forexample).

The invention accordingly provides from another aspect for the use ofthe dyes of the formula (I), their salts and mixtures for dyeing and/orprinting fibrous materials consisting of natural or syntheticpolyamides. A further aspect is the production of Inkjet printing inksand their use for printing fibrous materials consisting of natural orsynthetic polyamides.

Dyeing is carried out as per known processes, see for example the dyeingprocesses described in Ullmanns Encyklopädie der technischen Chemie, 4thEdition, 1982, Volume 22, pages 658-673 or in the book by M. Peter andH. K. Rouette, Grundlagen der Textilveredlung, 13th Edition, 1989, pages535-556 and 566-574. Preference is given to dyeing in the exhaustprocess at a temperature of 30 to 140° C., more preferably 80 to 120° C.and most preferably at a temperature of 80 to 100° C., and at a liquorratio in the range from 3:1 to 40:1.

The substrate to be dyed can be present in the form of yarn, wovenfabric, loop-formingly knitted fabric or carpet for example. Fullyfashioned dyeings are even permanently possible on delicate substrates,examples being lambswool, cashmere, alpaca and mohair. The dyes of theinvention are particularly useful for dyeing fine-denier fibres(microfibres).

The dyes according to the present invention and their salts are highlycompatible with known acid dyes. Accordingly, the dyes of the formula(I), their salts or mixtures can be used alone in a dyeing or printingprocess or else as a component in a combination shade dyeing or printingcomposition together with other acid dyes of the same class, i.e. withacid dyes possessing comparable dyeing properties, such as for examplefastness properties and exhaustion rates from the dyebath onto thesubstrate. The dyes of the present invention can be used in particulartogether with certain other dyes having suitable chromophores. The ratioin which the dyes are present in a combination shade dyeing or printingcomposition is dictated by the hue to be obtained.

The novel dyes of the formula (I), as stated above, are very useful fordyeing natural and synthetic polyamides, i.e. wool, silk and all nylontypes, on each of which dyeings having a high fastness level, especiallygood light fastness and good wet fastnesses (washing, alkalineperspiration) are obtained. The dyes of the formula (I) and their saltshave a high rate of exhaustion. The ability of the dyes of the formula(I) and their salt to build up is likewise very good. On-tone dyeings onthe identified substrates are of outstanding quality. All dyeingsmoreover have a constant hue under artificial light. Furthermore, thefastness to decating and boiling is good.

One decisive advantage of the novel dyes is that they are metal free andprovide very level dyeings.

The compounds according to the invention can be used as an individualdye or else, owing to their good compatibility, as a combination elementwith other dyes of the same class having comparable dyeing properties,for example with regard to general fastnesses, exhaustion value, etc.The combination shade dyeings obtained have similar fastnesses todyeings with the individual dye.

The invention's dyes of the formula (I) can also be used as redcomponents in trichromatic dyeing or printing. Trichromatic dyeing orprinting can utilize all customary and known dyeing and printingprocesses, such as for example the continuous process, exhaustionprocess, foam dyeing process and Ink-Jet process.

The composition of the individual dye components in the trichromatic dyemixture used in the process of the invention depends on the desired hue.A brown hue for example preferably utilizes 20-40% by weight of a yellowcomponent, 40-60% by weight of the invention's orange or red componentand 10-20% by weight of a blue component.

The yellow component, as described above, can consist of a singlecomponent or of a mixture of different orange individual componentsconforming to the formula (I). Preference is given to double and triplecombinations.

Particularly preferred red and/or yellow components are described inWO2002/46318.

In the examples which follow, parts and percentages are by weight andtemperatures are reported in degrees Celsius.

PREPARATION EXAMPLE 1

15.0 parts of 4-aminoacetanilide were introduced into a mixture of 50parts of ice and 25 parts by volume of approximately 30% hydrochloricacid and stirred for about 30 min. At 0-5° C. 17.3 parts by volume of a40% sodium nitrite solution were then added dropwise within 30 min. Thetemperature was maintained at 0-5° C. during the addition by addition ofice. After the diazotization had ended, excess sodium nitrite wasdestroyed with aminosulphonic acid.

29.1 parts of 3-[(ethylphenylamino)methyl]benzenesulphonic acid weresuspended in 200 parts of water. The suspension was adjusted to pH 7-7.5with sodium carbonate. The diazo suspension was then added in the courseof 30 min with vigorous stirring. During the addition, the pH wasmaintained at about 7 by metered addition of sodium carbonate solution.

After the coupling reaction had ended, 50 parts by volume of anapproximately 30% aqueous sodium hydroxide solution were added and thereaction mixture was heated to 90-100° C. The reaction was monitored bythin layer chromatography. After about 24 h, the deacetylation hadended. The resulting compound of the formula

was filtered off.

A suspension of 34.4 parts of2-(2′,6′-dimethylphenylamino)-8-hydroxynaphthalene-6-sulphonic acid in200 parts of water was admixed, at about 20-25° C. and a pH between 1and 2, with a diazonium salt solution prepared in a conventional mannerfrom 41.0 parts of the aminoazo compound (I) and 17.3 parts by volume ofa 40% sodium nitrite solution at 0-5° C. After coupling had ended, theresulting dye of the formula

was salted out with sodium chloride, filtered off and dried at 50° C.under reduced pressure. On wool and in particular on polyamide fibres itproduces blue dyeings having good light and wet fastness properties(lamda(max)(λ_(max))=588 nm).

EXAMPLES 2-53

The table which follows contains dyes which can be prepared similarly tothe method described in Example 1 by using the corresponding startingmaterials. These dyes provide blue dyeings having very good light andwet fastnesses on polyamide fibres and wool.

Example R₁ R₂ R₃ R₄ R₅ R₆ R₇ R₈ Position λ_(max) 2 Me Me H H H Me Et

p 592 3 Me Me H H H Me Et

m 585 4 Me Me H Me Me Me Et

p 596 5 Me Me H Me Me H Et

p 594 6 Me Me H Me H Me Et

p 591 7 Me Et H H H Me Et

p 593 8 Me Et H Me H H Et

p 592 9 Me Et H Me Me Me Et

p 594 10 Me Et H H H Me Et

p 588 11 Me Et H Me Me Me Et

p 597 12 Me Et H Me Me Me Et

p 593 13 Me Et H H H Me Et

p 592 14 Me Et H Me Me Me Et

p 597 15 Me Et H Me Me Me Me

p 596 16 Me Me H H H Me Et

p 589 17 Me Me H Me Me Me Et

p 592 18 Me Me H Me Me H Et

p 595 19 Me Et H H H H Et

m 587 20 Me Et H H H H Et

p 588 21 Me Et H Me Me H Et

p 591 22 Me Et H Me Me H Et

p 592 23 Me Et H Cl Cl H Et

p 599 24 Me Et H Cl Cl Me Et

p 601 25 Et Et H Cl Me Me Et

p 594 26 Et Et H H H Me Et

p 589 27 Et Et H H H Me Et

p 591 28 Et Et H H H Me Et

m 587 29 Me Me Me Me Me Me Et

p 596 30 Me Me Me Me Me H Et

p 594 31 Me Me Me H H Me Et

p 588 32 Me Me Me H H Me Et

p 590 33 Me i-Pr H H H Me Et

p 589 34 Me i-Pr H H H H Et

p 588 35 Me i-Pr H Me Me H Et

p 593 36 Me i-Pr H H Me H Et

p 591 37 Me i-Pr H Me H H Et

p 592 38 Me i-Pr H Me H H n-Pr

p 596 39 Me i-Pr H H H H Me

p 589 40 i-Pr i-Pr H H H H Et

p 587 41 i-Pr i-Pr H H H Me Et

p 586 42 i-Pr i-Pr H H H H Et

m 589 43 i-Pr i-Pr H H Me H Et

p 592 44 i-Pr i-Pr H Me Me Me Et

p 595 45 i-Pr i-Pr H Me Me Me Et

p 594 46 i-Pr i-Pr H H H Me Et

p 590 47 i-Pr i-Pr H Me Me H Et

p 592 48 Et Et H Me Me Me Et

p 593 49 Et Et H H H Me Et

p 588 50 Et Et H Me Me H Et

p 591 51 Me Me Me Me Me Me Et

p 590 52 Me Me Me H H Me Et

p 589 53 Me Me Me H H H Et

m 586

USE EXAMPLE A

A dyebath at 40° C., consisting of 2000 parts of water, 1 part of aweakly cation-active levelling agent which is based on an ethoxylatedaminopropyl fatty acid amide and which has affinity for dye, 0.25 partof the dye of Preparation Example 1 and adjusted to pH 5 with 1-2 partsof 40% acetic acid is entered with 100 parts of nylon-6 fabric. After 10minutes at 40° C., the dyebath is heated to 98° C. at a rate of 1° C.per minute and then left at the boil for 45-60 minutes. Thereafter it iscooled down to 70° C. over 15 minutes. The dyeing is removed from thebath, rinsed with hot and then with cold water and dried. The resultobtained is a blue polyamide dyeing possessing good light and wetfastnesses.

USE EXAMPLE B

A dyebath at 40° C., consisting of 2000 parts of water, 1 part of aweakly cation-active levelling agent which is based on an ethoxylatedaminopropyl fatty acid amide and which has affinity for dye, 0.3 part ofthe dye of Preparation Example 1 and adjusted to pH 5.5 with 1-2 partsof 40% acetic acid is entered with 100 parts of nylon-6,6 fabric. After10 minutes at 40° C., the dyebath is heated to 120° C. at a rate of 1.5°C. per minute and then left at this temperature for 15-25 minutes.Thereafter it is cooled down to 70° C. over 25 minutes. The dyeing isremoved from the dyebath, rinsed with hot and then with cold water anddried. The result obtained is a blue polyamide dyeing with goodlevelness and having good light and wet fastnesses.

USE EXAMPLE C

A dyebath at 40° C., consisting of 4000 parts of water, 1 part of aweakly amphoteric levelling agent which is based on a sulphated,ethoxylated fatty acid amide and which has affinity for dye, 0.4 part ofthe dye of Preparation Example 1 and adjusted to pH 5 with 1-2 parts of40% acetic acid is entered with 100 parts of wool fabric. After 10minutes at 40° C., the dyebath is heated to boiling at a rate of 1° C.per minute and then left at the boil for 40-60 minutes. Thereafter it iscooled down to 70° C. over 20 minutes. The dyeing is removed from thebath, rinsed with hot and then with cold water and dried. The resultobtained is a blue wool dyeing possessing good light and wet fastnesses.

USE EXAMPLE D

100 parts of a woven nylon-6 material are padded with a 50° C. liquorconsisting of

40 parts of the dye of Preparation Example 1, 100 parts of urea, 20parts of a nonionic solubilizer based on butyldiglycol, 15-20 parts ofacetic acid (to adjust the pH to 4), 10 parts of a weakly cation-activelevelling agent which is based on an ethoxylated aminopropyl fatty acidamide and has affinity for dye, and 810-815 parts of water (to make upto 1000 parts of padding liquor).

The material thus impregnated is rolled up and left to dwell in asteaming chamber under saturated steam conditions at 85-98° C. for 3-6hours for fixation. The dyeing is then rinsed with hot and cold waterand dried. The result obtained is a blue nylon dyeing having goodlevelness in the piece and good light and wet fastnesses.

USE EXAMPLE E

A textile cut pile sheet material composed of nylon-6 and having asynthetic base fabric is padded with a liquor containing per 1000 parts

1 part of dye of Preparation Example 1 4 parts of a commerciallyavailable thickener based on carob flour ether 2 parts of a nonionicethylene oxide adduct of a higher alkylphenol 1 part of 60% acetic acid.

This is followed by printing with a paste which per 1000 parts containsthe following components:

20 parts of commercially available alkoxylated fatty alkylamine(displace product) 20 parts of a commercially available thickener basedon carob flour ether.

The print is fixed for 6 minutes in saturated steam at 100° C., rinsedand dried. The result obtained is a level-coloured cover material havinga blue and white pattern.

USE EXAMPLE F

A dyebath at 40° C. consisting of 2000 parts of water, 1 part of aweakly cation-active levelling agent which is based on an ethoxylatedaminopropyl fatty acid amide and has affinity for dye, 0.2 part of thedye of Example 8 of WO2002/46318, 1.5 parts of a commercially availablepreparation of C.I. Acid Yellow 236 (Nylosan Yellow F-L) and 0.5 part ofthe blue dye of Preparation Example 1 of this patent application whichis adjusted to pH 5 with 1-2 parts of 40% acetic acid is entered with100 parts of woven nylon-6,6 fabric. After 10 minutes at 40° C., thedyebath is heated to 98° C. at a rate of 1° C. per minute and then leftat the boil for 45 to 60 minutes. This is followed by cooling down to70° C. over 15 minutes. The dyeing is removed from the bath, rinsed withhot and then with cold water and dried. The result obtained is a levelgrey polyamide dyeing having good light and wet fastnesses.

USE EXAMPLE G

100 parts of a chrome-tanned and synthetically retanned shave-moistgrain leather are dyed for 30 minutes in a bath of 300 parts of waterand 2 parts of the dye of Preparation Example 1 at 55° C. After additionof 4 parts of a 60% emulsion of a sulphited fish oil, the leather isfatliquored for 45 minutes. It is then acidified with 8.5% formic acidand milled for 10 minutes (final pH in the bath 3.5-4.0). The leather isthen rinsed, allowed to drip dry and finished as usual. The resultobtained is a leather dyed in a level clear blue hue with goodfastnesses.

Use Examples A to G can also be carried out with dyes 2 to 53 withsimilar results.

USE EXAMPLE H

3 parts of the dye of Preparation Example 3 are dissolved in 82 parts ofdemineralized water and 15 parts of diethylene glycol at 60° C. Coolingdown to room temperature gives a blue printing ink which is very highlysuitable for ink jet printing on paper or polyamide and wool textiles.

Use Example H can also be carried out with dyes 1 or 2 and 4 to 53 withsimilar results.

USE EXAMPLE I

A dyebath consisting of 1000 parts of water, 80 parts of calcinedGlauber salt, 1 part of sodium nitrobenzene-3-sulphonate and 1 part ofdye from Example 79 is heated to 80° C. in the course of 10 minutes.Then, 100 parts of mercerized cotton are added. This is followed bydyeing at 80° C. for 5 minutes and then heating to 95° C. in the courseof 15 minutes. After 10 minutes at 95° C., 3 parts of sodium carbonateare added, followed by a further 7 parts of sodium carbonate after 20minutes and another 10 parts of sodium carbonate after 30 minutes at 95°C. Dyeing is subsequently continued at 95° C. for 60 minutes. The dyedmaterial is then removed from the dyebath and rinsed in runningdemineralized water for 3 minutes. This is followed by two washes for 10minutes in 5000 parts of boiling demineralized water at a time andsubsequent rinsing in running demineralized water at 60° C. for 3minutes and with cold tap water for one minute. Drying leaves abrilliant blue cotton dyeing having good fastnesses.

USE EXAMPLE J

0.2 part of the dye of Preparation Example 1 is dissolved in 100 partsof hot water and the solution is cooled down to room temperature. Thissolution is added to 100 parts of chemically bleached sulphite pulpbeaten in 2000 parts of water in a Hollander. After 15 minutes ofcommixing the stuff is sized with resin size and aluminium sulphate in aconventional manner. Paper produced from this stuff has a blue shadewith good wet fastnesses.

Use Examples I and J can also be carried out with dyes 2 to 53 withsimilar results.

1. A compound of formula (I)

wherein R¹ and R² are independently selected from the group consistingof unsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, and substituted branched C₃₋₆alkyl, R³is selected from the group consisting of hydrogen, unsubstitutedunbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl, substitutedunbranched C₁₋₆alkyl, and substituted branched C₃₋₆alkyl, R⁴ and R⁵ areindependently selected from the group consisting of hydrogen,unsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, substituted branched C₃₋₆alkyl, andhalogen, R⁶ is selected from the group consisting of hydrogen,unsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, substituted branched C₃₋₆alkyl,unsubstituted unbranched C₁₋₆alkoxy, unsubstituted branched C₃₋₆alkoxy,substituted unbranched C₁₋₆alkoxy, substituted branched C₃₋₆alkoxy,halogen, —NHCO—(C₁₋₆alkyl) with an unbranched C₁₋₆alkyl group, which issubstituted or unsubstituted, —NHCO—(C₃₋₆alkyl) with a branchedC₃₋₆alkyl group, which is substituted or unsubstituted, and —NHCONH₂, R⁷and R⁸ are independently selected from the group consisting ofunsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, substituted branched C₃₋₆alkyl, aryl,and —(CH₂)_(n)-aryl where n=1, 2, 3 or
 4. 2. A compound according toclaim 1 wherein R¹ and R² are independently selected from the groupconsisting of unsubstituted unbranched C₁₋₆alkyl, unsubstituted branchedC₃₋₆alkyl, substituted unbranched C₁₋₆alkyl, and substituted branchedC₃₋₆alkyl, R³ is selected from the group consisting of hydrogen,unsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, and substituted branched C₃₋₆alkyl, R⁴and R⁵ are independently selected from the group consisting of hydrogen,unsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, substituted branched C₃₋₆alkyl, andhalogen, R⁶ is selected from the group consisting of hydrogen,unsubstituted unbranched C₁₋₆alkyl, unsubstituted branched C₃₋₆alkyl,substituted unbranched C₁₋₆alkyl, substituted branched C₃₋₆alkyl,unsubstituted unbranched C₁₋₆alkyl, substituted branched C₃-C₆alkyl,unsubstituted unbranched C₁₋₆alkoxy, unsubstituted branched C₃₋₆alkoxy,and substituted unbranched C₁₋₆alkoxy, R⁷ is selected from the groupconsisting of unsubstituted unbranched C₁₋₆alkyl, unsubstituted branchedC₃₋₆alkyl, substituted unbranched C₁₋₆alkyl, and substituted branchedC₃₋₆alkyl, R⁸ is aryl or —(CH₂)_(n)-aryl where n=1, 2, 3 or
 4. 3. Acompound according to claim 1 wherein the compound of the formula (I) issubstituted with at least one anionic substituent.
 4. A compoundaccording to claim 3 wherein the compound of the formula (I) issubstituted with at least one sulpho group.
 5. A process for preparing acompound of formula (I) according to claim 1, comprising the steps of:diazotizing and coupling the amine functions of the compound of theformula (II)

where SG is a protective group, onto one equivalent of a compound of theformula (III)

subsequently removing the protective group SG to produce an amine of theformula (IV)

and diazotizing and coupling the amine of the formula (IV) at acidic pHonto one equivalent of a compound of the formula (V)

where the substituents are each as defined above.
 6. A process fordyeing and/or printing an organic substrate comprising the step ofcontacting the organic substrate with at least one compound according toclaim
 1. 7. A process for dyeing and/or printing a wool, silk and/or asynthetic polyamide substrate, comprising the step of contacting thewool, silk and/or synthetic polyamide substrate with at least onecompound according to claim
 1. 8. A process for preparing a printing inkfor the InkJet process comprising the step of adding at least onecompound according to claim 1 to at least one additional inkjet inkcomponent.
 9. A process for preparing a compound of formula (I)according to claim 1, comprising the steps of: diazotizing and couplingat acidic pH the compound of the formula (II′)

wherein SG is a protective group, onto one equivalent of a compound ofthe formula (V)

subsequently removing the protective group SG to produce the amine ofthe formula (IV′)

and diazotizing and coupling the amine of the formula (IV′) onto oneequivalent of a compound of the formula (III)

where the substituents are each as defined above.
 10. An organicsubstrate dyed and/or printed by a process according to claim
 6. 11. Awool, silk and/or synthetic polyamide substrate dyed and/or printed by aprocess according to claim
 7. 12. An inkjet ink comprising at least onecompound according to claim 1.